A bit off topic but this may be relevent. I have done a lot of sea kayak coaching. Most people who come on courses like to get the bit of paper at the end of the weekend no matter what age, it acts as a bit of motivation to take the course seriously. We often had scouts come along who needed the piece of paper so they could become instructors. Many of them had been kayaking for many years but had had few lessons. When asked to do simlpe things like going backwards in a straight line they were often surprisingly poor. At the end of the course they would complain if not given the certificate, " hey I did the course, what does it matter?"
Even if you have a lot of experience you do not always learn how to do everything. A lot is down to attitude, the people with the best attitude, never too old to learn something, often made the best improvements. Those who thought they already knew it all were the most difficult to help.
Having said that this will only be the case if the instructor is a good one, so recommendation are priceless.